Development of vital wheat gluten in non-aqueous media

ABSTRACT

The present invention relates to the development of vital wheat gluten in non-aqueous media. The gluten which have been developed in such a way can easily be stored for a prolonged period. The gluten are used in the preparation of chewable consumable products, or in processed food and feed.

TECHNICAL FIELD

[0001] The present invention relates to the development of vital wheatgluten in non-aqueous media. The gluten which have been developed insuch a way can easily be stored for a prolonged period of time underambient storing conditions. The gluten are used in the preparation ofchewable consumable products, they are also used in processed foods andfeeds.

BACKGROUND OF THE INVENTION

[0002] Conventional chewing gums have achieved a broad success in themarketplace. Such chewing gums are typically made of a gum base and acoating. Both of these parts further contain compounds, which act assweeteners, colourants, flavours, preservatives and processing aids.Such ingredients also serve to modify the bite and taste of the product.

[0003] Conventional gum bases may be chosen from natural or syntheticresins such as chicle, natural rubber, guttapercha, lechi capsi, sorva,guttakay, crown gum, butadiene-styrene copolymers, polyisobutylene,isobutylene-isoprene copolymers, polyvinyl acetate, and polyvinylalcohol. The gum base, which is water insoluble and chewable furthercomprises elastomers, resins, fats, oils, waxes, softeners and fillers.As a softener or plasticiser the following molecules can be usedlanolin, propylene glycol, glycerine or triacetin in amounts of up to 10weight %. Other additives include fillers and anti-sticking agents.

[0004] The products used as basic ingredient for the gum base are notbiodegradable and do not degrade upon chewing either. This distinguishesthe chewing gum from the chewy candies, which are completely digestible.Disposal of conventional chewing gum can cause unsightly litter.

[0005] Wheat gluten has been tried as a digestible and biodegradablealternative to the mentioned gum base ingredients. In addition to theirbeing biodegradable when discarded the gluten, because they areproteins, are not harmful to the human body should they be swallowed. Tothe contrary, gums based on or including gluten would be nutritious.

[0006] U.S. Pat. No. 3,814,815 describes a method of manufacturing a gumbase in which gluten are denatured by more than 10% and preferablybetween 10 and 60%. Denaturation is described to be performed in anexcess of water either by heating or freezing. International patentapplication WO 95/12322 discloses the use of gluten as a gum base forchewing gum. In order to improve the chewability characteristics thegluten are cross-linked with a protein condensing agent, preferablytannin. It is recognized that the gluten-based chewing gums have a highmoisture content, which renders the gums susceptible to microbialspoilage. In order to avoid this spoilage preservatives are added.

[0007] WO 94/17673 describes an improvement in the chew of gluten whenused as a gum base wherein the improvement consists in the addition of atexturizing agent.

[0008] U.S. Pat. No. 3,692,535 relates to the preparation ofready-to-bake pie crust. The pie crust is said to be shelf stablewithout refrigeration and can be rolled or otherwise handled withoutcrumbling or breaking. As indicated in the description (col.2, lines3-21,) the complete flour is developed in water. This necessitates theaddition of preservatives to inhibit microbial growth.

[0009] U.S. Pat. No. 5,366,740 relates to the use of a combination ofspray dried and flash dried gluten as a chewing gum base.

[0010] U.S. Pat. No. 5,665,152 relates to the forming of solid,non-edible biodegradable, grain protein-based articles.

[0011] U.S. Pat. No. 5,945,142 relates to the addition of small amountsof gluten to the norma chewing gum base in order to reduce thesqueakiness.

[0012] Despite the fact that gluten have found acceptance in a widerange of applications gluten have to date not gained a reasonablemarkets share in food or feed applications. In the chewing gum field theuse of gluten has been hampered by a number of organoleptic factors andno gluten based chewing gum has gained wide acceptance in the market,regardless of the advantages of degradability and edibility of thegluten. In addition to the organoleptic factors one of the reasonstherefore is the wide-spread belief that it is necessary to develop thegluten in an aqueous medium. Development in an aqueous medium results inthe presence of too much water in the final product, which makes theproduct perishable due to the growth of microorganisms. The presentinvention solves this problem.

SUMMARY OF THE INVENTION

[0013] It is an object of the present invention to provide a digestible,degradable gluten basic composition which, can be stored for a prolongedperiod of time without degradation and which can be used as a gum basefor chewing gums, chewable candies, and processed food or feed. Thestorage conditions are the normal storage conditions for gluten.

[0014] The present invention discloses a developed vital wheat glutenwherein the development was performed in a non-aqueous medium i.e. amedium having a Aw of less then 0.8, or with a Aw so that the finalcomposition has a Aw less than 0.7 A preferred medium for developing thegluten is a concentrated carbohydrate solution, containing less than 30%of water, preferably less than 20%, more preferably less than 10% (w/w).

[0015] The present invention also discloses a method for developingwheat gluten in a non-aqueous medium. The method comprises the steps of

[0016] mixing gluten 20-60% (d.s. w/w) with a non-aqueous medium,

[0017] kneading the mixture at a temperature of between 50 and 90° C.,

[0018] continuing the kneading until the value of at least 75% of themaximal torque is reached,

[0019] shaping the gluten into a desired form.

[0020] The present invention further discloses the use of theso-developed wheat gluten as a gum base for chewing gums, or as basisfor chewing candies.

[0021] Wheat gluten developed in non-aqueous media has been applied infood applications but also in bakery and processed food. The wheatgluten was further applied in feed applications such as in pet food orfish feed.

BRIEF DESCRIPTION OF THE FIGURES

[0022]FIG. 1 shows a Brabender Plastogram recorded on a Do-Corder DC2200-3 (Brabender OHG, Duisburg), expressing the evolution of the torque(Nm) as a function of time when kneading a mixture ofgluten-glycerol-water (50:50:15) at 58° Celsius and 25 rpm.

DETAILED DESCRIPTION OF THE INVENTION

[0023] It is an object of the present invention to provide a digestible,degradable gluten basic composition, which can be stored for a prolongedperiod of time without degradation and which can for example be used asa gum base for chewing gums or chewable candies. The present inventiondiscloses a developed vital wheat gluten wherein the development wasperformed in a non-aqueous medium i.e. a medium having a Aw (wateractivity) of less than 0.8, so that the final composition has a Aw ofless than 0.7.

[0024] In general terms, the wheat gluten are developed by mixing a highconcentration of vital wheat gluten with the non-aqueous medium ofchoice. Kneading of this mixture is continued until the torque ismaximal (see FIG. 1). It is especially at the maximum value of thistorque that the product has excellent chewing properties. The productcan now be used as a gum base. When mixing is stopped before the maximumvalue, or beyond the maximum value, the product will be more suitablefor applications in chewy candy, in processed food, or in feedapplications (including pet food). In general we have found that thekneading is to continue until at least 75% of the maximum torque valueis reached (note that this can be before or after the maximum value),preferably until at least 85% is reached. Since the wheat gluten weredeveloped in a non-aqueous medium the product is stable towardsmicrobial degradation and can be stored for several months withoutdeterioration, under normal storage conditions This greatly adds to theflexibility of the use of vital wheat gluten.

[0025] In a typical preparation the kneading is performed at atemperature between 50 and 90° C. The essence of the kneading is thatsufficient energy has to be added to allow the gluten to unfold, andrestore their interactions i.e. H-bridges, hydrophobic and ionic bonds,sulpher bridges and crosslinks. This means that there is someflexibility as to the type of kneader (type, continuous or batch,extruder etc.) and the conditions under which the kneader is employed.This is what is understood by developing according to the presentinvention. Unfolding and restoration of interactions is not accompaniedby a substantial breakdown of the primary structure of the proteins.Such a process is called denaturation and that is not desirable at leastnot to an extensive degree in the present case.

[0026] The evolution of the torque (time to maximum) and the height ofthe torque can be influenced by altering the conditions of the kneading,i.e. temperature, speed of kneading, inclusion of other ingredients oradditives, etc. Some of these parameters are illustrated in theexamples. Kneading times are typically between 5 min and 1 hourpreferably between 10 and 25 minutes. It should be kept in mind thatwhat counts is the energy transfer properties of the mixer. Where anextruder is used the treatment time is in the order of seconds. Althoughthe present invention relates to the absence of water typically up toabout 20% of water may be present. The limits for this are determined bythe fact that the water activity (Aw) has to be such that microbialgrowth is not possible. This water activity limit depends to a certainextent on the type of microorganism. In addition it should be noted thatin the presence of water kneading becomes easier. A preferred medium isa concentrated carbohydrate solution, containing less than 30% of water,preferably less than 20%, more preferably less than 10% (w/w). Theamount of water, which is present during kneading influences thekneading conditions. Kneading becomes easier in the presence of water.In fact what is essential for the present invention is the wateractivity of the final product.

[0027] The gluten used in the present invention can be from any cerealsource, advantageously they are wheat gluten and most preferred are thevital wheat gluten. It is possible to combine gluten from differentsources and it is also possible to use partially vital gluten.

[0028] After development of the gluten they are shaped in a desiredform. They can be moulded or forced through a die. Additional componentsand ingredients are added depending on the type of product which is tobe obtained. When used for preparing chewing gum it is possible to usethe gluten as presently developed as base. The gluten can also becombined with other biodegradable components such as crosslinkingproteins. It is further possible to combine the gluten of the presentinvention with normal synthetic or natural gum bases.

[0029] The present invention discloses the use of the so-developed wheatgluten as a gum base for chewing gums or chewing candies. The wheatgluten has been applied in food applications including in bakery andprocessed food. The wheat gluten was further applied in feedapplications such as in pet food. In such cases it may be necessary toprocess the gluten by cooking, baking or other means.

EXAMPLES

[0030] 1. 50 g vital wheat gluten (94% dry substance (Gluvital® 21000))were mixed with 50 g glycerol and 10 g of water, and kneaded in aDo-Corder (Brabender,Duisburg, 50 g bowl) at 58° C. at 25 rpm. After 1minute the torque increased, and reached a maximum of 8.5 Nm after 13min, after which it started declining (see FIG. 1). The productrecovered when kneading up to the top of the development curve hasexcellent chewing properties and can be used as gum base for e.g.chewing gum formulas.

[0031] 2. 50 g vital wheat gluten (94% dry substance (Gluvital® 21000))were mixed with 50 g glycerol and 6 g lecithin (Stem, Hamburg), andkneaded in a Do-Corder at 58° C. at 25 rpm. After 4 minute the torqueincreased, and reached a maximum of 4.5 Nm after 18 min, after which itstarted declining. The product recovered when kneading up to the top ofthe development curve has excellent chewing properties and can be usedas gum base for e.g. chewing gum formulas. The product was stabletowards microbiological degradation, and was stored for several months.

[0032] 3. 50 g vital wheat gluten (94% dry substance (Gluvital® 21000))were mixed with 50 g glycerol, and 15 g water, and kneaded in aDo-Corder at 58° C. at 25 rpm. After 2 minutes the torque increased, andreached a maximum of 6.5 Nm after 15 min, after which it starteddeclining. The consistency of the product is higher than in example 1,and a different ‘bite’ was obtained. The water activity was still lowenough to avoid microbiological degradation of the product.

[0033] 4. 50 g vital wheat gluten (94% dry substance (Gluvital 21000))were mixed with 50 g glycerol, and 5 g water, and kneaded in a Do-Corderat 58° C. and a speed of resp. 25, 50, 100 and 160 rpm. It was foundthat the time to reach the high torque declines with increasing mixerspeed.

[0034] 5. 50 g vital wheat gluten (94% dry substance (Gluvital 21000))were mixed with 81.25 g (80% dry substance) glucose syrup (CISweet™ D01608, Cerestar), 18.75 g water, 1 g of lecithin, 3 g of cocosfat, 10 gof tapioca starch in the 50 g bowl of the Do-Corder at resp. 40. 60 and80° C., at 150 rpm. Increasing the temperature hardly influences thelevel of the maximum torque, but drastically influences the time atwhich this maximum is reached.

[0035] 6. 50 g vital wheat gluten (94% dry substance (Gluvital 21000))were mixed with 81.25 g (80% dry substance) glucose syrup (CISweet D01608, Cerestar), 18.75 g water, 1 g of lecithin, and 3 g of cocosfat inthe 50 g bowl of the Do-Corder at 58° C. and kneaded at 150 rpm. Theproduct was a directly consumable chewable product.

[0036] 7. 50 g vital wheat gluten (94% dry substance (Gluvital 21000))were mixed with 81.25 g (80% dry substance) glucose syrup (CISweet D01608, Cerestar), 18.75 g water, 1 g of lecithin, 3 g of cocosfat, 10 gof rice flour and 0.1 g of mint flavour in the 50 g bowl of theDo-Corder at 58° C. and 150 rpm. The maximum torque is the same aswithout the filler (rice flour), but the maximum is reached after ashorter time, due to the higher dry substance of the mixture. Theproduct was a directly consumable chewable product.

[0037] 8. A product was produced as in example 6, and after kneading toits maximal torque it was shaped after which it was fried yieldingsnacks.

[0038] A part of the same product was baked (conventional, microwave orcombi-oven) yielding nice bakery products with baguette-like crumbstructure.

[0039] 9. 40 g vital wheat gluten (94% dry substance (Gluvital 21000))were mixed with 40 g of dried (96% dry substance) corn germs (40% oil)and 25 g of water, and kneaded in the 50 g bowl of the Do-Corder at 58°C. and 25 rpm. A nutritionally excellent product is generated for petsthat easily can be further processed cooked, fryed, baked, sterrilisedin cans, etc. It is also an excellent fish feed, both through itscomposition (high protein, high fat, low carbohydrates) and itsproperties (consistant mass that is not desintegrating when dropped inwater).

[0040] 10. 50 g of vital wheat gluten 94% dry substance (Gluvital 21000)were mixed with 50 g of corn gluten (88% dry substance) and 25 g ofwater in the 50 g bowl of the Do-Corder at 58° C. and 25 rpm. A nice,nutritionally very interesting product was obtained that can be shapedand further processed through the normal processes applied in pet food,animal feed and fish feed. onset maximum time development torque tomaximum time to 9 Nm example (min) (Nm) (min) (min) 1 1 8.5 13 2 4 4.518 3 2 6.5 15 4 (25 rpm) 5 21 4 (50 rpm) 3 13.5 4 (100 rpm) 2 12 4 (160rpm) 1 5.5 5 (40° C.) 4 3.5 58 5 (60° C.) 3 3.5 11 5 (80° C.) 2 3 6 6 93.5 19 7.8 4 4 12 9 1 4 10 10 1 5 3

[0041] 11. 1 kg of vital gluten (94% dry substance (Gluvital 21000))were mixed with 1.625 kg (80% dry substance) glucose syrup (C*Sweet D01608, Cerestar), 0.375 kg of water, 0.2 kg of rice flour, 20 g oflecithin and 60 g of cocosfat in a Z-blade mixer at 58° C. 500 ppmcalcium peroxide and 500 ppm of tannin were added as crosslinkingagents. The energy transfer of this mixer was lower than that of theDo-Corder, which resulted in times to optimal development (maximaltorque) of 25 min. 2 min. before reaching the maximum 10 ml of mintflavour were added. At the maximum torque the kneading was stopped andthe product shaped: first laminated to sheets of different thickness(resp. 3, 5 and 8 mm), and cut into desired forms. The products could beeasily sanded and coated: for sanding the products were damped withsteam, and dropped in fine sugar, dextrose, or any other powder used forthis purpose. The coating process was executed with sucrose (66° Brix)or dextrose solutions (48% solids) to which flavour (peach, lemon etc.)was added. The products were put on sieves or screens, and the coatingsolution poured on it. The products could be consumed as chewing gums.

[0042] 12. 1 kg of vital gluten (94% dry substance (Gluvital 21000))were mixed with 1.625 kg (80% dry substance) glucose syrup (C*Sweet D01608, Cerestar), 0.2 kg of water, 0.09 kg of glycerol, 0.2 kg of riceflour, 20 g of lecithin and 60 g of cocosfat in a Z-blade mixer at 58°C. 500 ppm calcium peroxide and 500 ppm of tannin were added ascrosslinking agents, together with 35 ml of a 50% sodium citratesolution and 1 ml of yellow colour. The energy transfer of this mixerwas lower than that of the Do-Corder, which resulted in times to optimaldevelopment (maximal torque) of 25 min. 2 min before reaching themaximum 15 ml of orange flavour were added. At the maximum torque thekneading was stopped and the product shaped: first laminated to sheetsof different thickness (resp. 3. 5 and 8 mm), and cut into desiredforms. The products could be easily sanded and coated as described inexample 11.The products could be consumed as chewing gums.

[0043] 13. 1 kg of vital gluten (94% dry substance (Gluvital 21000))were mixed with 1.625 kg (80% dry substance) glucose syrup (C*Sweet D01608, Cerestar), 0.2 kg of water, 0.09 kg of glycerol, 0.2 kg of riceflour, 20 g of lecithin and 60 g of cocosfat in a Z-blade mixer at 58°C. 500 ppm calcium peroxide and 500 ppm of tannin were added ascrosslinking agents, together with 35 ml of a 50% sodium citratesolution and 1 ml of yellow colour. The energy transfer of this mixerwas lower than that of the Do-Corder, which resulted in times to optimaldevelopment (maximal torque) of 25 min. 2 min before reaching themaximum 15 ml of orange flavour were added. 5 min after the maximumtorque was reached, the kneading was stopped and the product shaped:first laminated to sheets of different thickness (resp. 3. 5 and 8 mm),and cut into different forms. The products could be easily sanded andcoated as described in Example 11. Very nice sweets with a chewy candytexture were obtained. The tests were repeated at higher temperatures(85° C.). The resulting products had a harder texture.

[0044] 14. 3 kg of vital gluten (94% dry substance (Gluvital 21000))were mixed with 4.875 kg (80% dry substance) glucose syrup (C*Sweet D01608, Cerestar), 1.125 kg of water, 0.6 kg of rice flour, 60 g oflecithin and 180 g of cocosfat in a large Z-blade mixer at 58° C. 1% ofiron(III)oxide were added as colouring agent. The energy transfer ofthis mixer was identical to that of the Do-Corder, i.e. development timewas only 15 min. 2 min before reaching the maximum 12 meat bouilloncubes were added After the kneading the mass was divided in differentlumps. After cooling down the mass hardened, looked as a roast beef, andcould be easily sliced. Other lumps were laminated and cut into smallcubes (0.5*0.5*0.5 cm³) for pet food applications (cats). We also shapedlumps into beef steak like mass. The tests were repeated with differentcolouring levels (resp. 0.25 and 0.1% iron oxide), and different favours(e.g. 0.1% chicken extract). The products were very much appreciated bydogs. After cooking the texture is close to that of boiled meat.

[0045] 15. 3 kg of vital gluten (94% dry substance (Gluvital 21000))were mixed with 4.875 kg (80% dry substance) glucose syrup (C*Sweet D01608, Cerestar), 1.125 kg of water, 0.6 kg of rice flour, 60 g oflecithin and 180 g of cocosfat in a large Z-blade mixer at 58° C. Whenall ingredients were well mixed, the mass was transferred to a pilotplant extruder (Clextral) with a screw configuration that correctlydevelopped the gluten. The hardness and texture of the products variedwith the kneading temperature: at 85° C. exit temperature the productwas a very soft, white-yellow dough that hardened on cooling down.Depending on the configuration of the exit of the extruder (die shapeand diameter, cutting knife etc.) different shaped products could beproduced. Also moulding of the mass into different forms was possible.The structure of the product varied with varying screw configuration:intensifying the kneading induced the formation of fibre-like structuresAt temperatures above 100° C. the products became crumble, but hardenedon cooling down, yielding snack-like products. Here too, the final shapecould be adapted by changing the extruder die.

1. A method for developing wheat gluten characterized in that the wheatgluten are developed in a non-aqueous medium.
 2. A method according toclaim 1 wherein the non-aqueous medium contains less than 20% of water,preferably less than 15%, more preferably less than 10%.
 3. A methodaccording to claim 1 wherein the non-aqueous medium has a water activitywhich is below 0.8
 4. A method according to claim 3 wherein the finalproduct has a water activity of less than 0.7.
 5. A method according toclaim 1 or 2 wherein the non-aqueous medium is a concentratedcarbohydrate syrup.
 6. A method according to claim 4 wherein thecarbohydrate is selected from the group consisting of glycerol, glucose,fructose, sucrose, invert sugar, sorbitol, and lactose.
 7. A method ofdeveloping wheat gluten according claim 1 wherein the gluten are vitalgluten.
 8. A method for developing wheat gluten comprising the steps ofmixing gluten 20-60% (d.s. w/w) with a non-aqueous medium, kneading themixture at a temperature of between 50 and 90° C., continuing thekneading until the value of at least 75% of the maximal torque isreached, shaping the gluten into a desired form.
 9. A method accordingto claim 8 wherein the water activity of the non-aqueous medium is below0.8.
 10. A method according to claim 8 wherein the kneading is continuedafter reaching the maximal torque and halted before 75% of the maximalvalue is reached.
 11. A method according to claim 8 wherein during thelater stage of the kneading, before, during or after shaping otheringredients are added to the gluten.
 12. A food or feed productcomprising a wheat gluten which has been developed in a non-aqueousmedium.